Metal complexes of dithiobiurets

ABSTRACT

METAL COMPLEXES OF KITHIOIURETS HAVE BEEN FOUND TO EXHIBIT EFFECTIVE FUNGICIDAL AND GROWTH REGULATING ACTIVITY. EXEMPLARY OF SUCH COMPOUNDS ARE THOSE REPRESENTED BY THE FOLLOWING STRUCTURE:   R1-N(-R2)-C(=Y)-N(-N(-R5)-R6)-C(=Y)-N(-R3)-R4 M-(X)N   WHEREIN R1-R6 ARE EACH SELECTED FROM A GROUP CONSISTING OF HYDROGEN, C1-C10 ALKYL, C2-C10 ALKENYL, C3-C10 CYCLOALKYL OPTIONALLY SUBSTITUTED WITH C1-C6 ALKYL CHLORO, BROMO, C6-C10 ARYL, OPTIONALLY SUBSTITUTED WITH C1-C6 ALKYL, CHLORO, BROMO, C7-C10 ARYLALKYL, C7-C10 ALKARYL. R1 AND R6 AND/OR R3 AND R4 AND0OR R5 AND R6 TOGETHER CAN BE A CARBOCYLCLIC RING CONTAINING ONE OR MORE HETEROATOMS SUCH AS N OR S; M IS ONE SELECTED FROM THE GROUP CONSISTING OF ZINC, IRON, NICKEL, COPPER, MANGANESE AND COBALT; X IS AN ANION BEING ONE SELECTED FROM THE GROUP CONSISTING OF CHLORIDE, BROMIDE, IODIDE, SULFATE, NITRATE, PHOSPHATE AND ACETATE; N IS AN INTEGER DETERMINED BY THE VALENCE OF THE METAL ATOMS, AND Y IS EITHER O OR S.

Patented Aug. 22, 1972 US. Cl. 260-439 R Claims ABSTRACT OF THEDISCLOSURE Metal complexes of dithiobiurets have been found to exhibiteffective fungicidal and growth regulating activity. Exemplary of suchcompounds are those represented by the following structure:

wherein R -R are each selected from a group consisting of hydrogen, C Calkyl, (D -C alkenyl, C 43 cycloalkyl optionally substituted with C -Calkyl chloro, bromo, C -C aryl, optionally substituted with C -C alkyl,chloro, bromo, C7-C1o arylalkyl, C -C alkaryl.

R and R and/ or R and R and/ or R and R together can be a carbocyclicring containing one or more heteroatoms such as N or S; M is oneselected from the group consisting of zinc, iron, nickel, copper,manganese and cobalt; X is an anion being one selected from the groupconsisting of chloride, bromide, iodide, sulfate, nitrate, phosphate andacetate; n is an integer determined by the valence of the metal atoms,and Y is either 0 or S.

This invention relates to the use of metal complexes of dithiobiurets asgrowth regulants and fungicides.

In one aspect this invention relates to the use of the aforesaidcompounds as fruit-thinning agents. In another aspect, this inventionrelates to the use of the aforesaid compounds as plant growth regulants.In yet another aspect, this invention relates to the use of theaforesaid compounds as crop harvest aids. In another aspect, thisinvention relates to the use of the aforesaid compounds as fungicides.

The broad class of growth regulants are those compounds ha'ving anability to regulate vegetative, flowering and fruiting characteristicsof crops produced throughout the world. With growth regulators, it isnow possible to chemically control and alter the physiological processesin the growing crop, which up until the advent of such technology couldonly be triggered by natural and climatic conditions. Thus, it ispossible to produce crops of higher quality and with greater flexibilityin harvesting procedures. Various theories have been proposed forexplaining the mechanisms of chemical growth regulants such as, theyprevent fertilization of freshly-opened flowers by inducing anincompatible condition between the stylar tissue and the pollen tubes.Another theory is that a crop is thinned because of an increased drop inyoung fruitlets due to accelerated ethylene generation by the particulartreatment. Developing fruitlets on weak spurs with a limited food supplymay be more susceptible than those with an abundant supply so that theelimination of clusters where two or more fruits have set on the samespur can be explained on the basis of competition for food; that is, thefruitlets having the greatest advantage for food supply possess the mostresistance to the chemical treatment.

Whatever may be the actual mechanism involved in chemical fruit thinningor in the removal of unwanted growth for particular plants, or in theabscission of the fruit when the plant matures, thereby regulating theharvest season, the growth regulants have indeed opened up an entirelynew field for agricultural chemicals.

An object of the present invention is to provide a process for thinningfruit plants, such as citrus, stone and porne fruits, small fruits andnuts, in which a chemical material may be employed within a relativelynarrow range of concentrations without danger of either overthinning, orcausing foilage and fruit damage. Another object of the invention is toprovide a process of thinning fruits with a chemical agent which caneffectively be applied to the trees over a relatively long period oftime beginning with full bloom.

Yet another object of the invention is to provide a process foradjusting the rate and timing of abscission of undesirable late fiowersand fruitlets prior to mechanical harvesting of mature crops.

A still further object of the invention is to provide a process forcontrolling the rate of final development and maturation of crops so asto regulate the timed abscission of the mature fruit, vegetables, nutsor berries.

A still further object of the invention is to provide a process fordelaying the onset of normal maturation processes, such as, senescenceor defoliation, thereby providing continued 'vegetative growth, as wellas more intensely colored foilage.

A still further object of the invention is to prevent thephotodegradation of dithiobiurets without in any way impairing itsgrowth regulating or fungicidal activity.

Other objects and many of the attended advantages of this invention willbe readily appreciated as the same becomes better understood byreference to the following detailed description.

Briefly, this invention relates to a method for regulating the growth ofplants, said method comprising the step of treating growing plants witha material of the group consisting of those compounds represented by oneof the following formulae:

wherein R -R are each selected from a group consisting of hydrogen, C Calkyl, C C alkenyl, C -C cycloalkyl optionally substituted With C -Calkyl chloro, bromo, C C aryl, optionally substituted with C C alkyl,chloro, bromo, CI -C arylalkyl, C -C alkaryl.

R and R and/ or R and R and/ or R and R together can be a carbocyclicring containing one or more heteroatoms such as N or S; M is oneselected from the group consisting of zinc, iron, nickel, copper,manganese and cobalt; X is an anion being one selected from the groupconsisting of chloride, bromide, iodide, sulfate, nitrate, phosphate andacetate; n is an integer determined by the valence of the metal atoms,and Y is either 0 or S.

Specific examples of compounds having the above structure are listedhereinbelow:

Compound N o.

1 Ferric chloride adduct of1,1,5,5-tetramethyl-3-dimethylaminodithiobiuret.

2 Zinc chloride adduct 0f1,1,5,5-tetramethyl-3-pentamethyleneamlnodithiobiuret.

Compound 7 Cupric chloride adduct oi1,1,5,5-tetraethyl-3-hexamcthyleneaminodithiobiuret.

8 Nickel chloride adduct oi1,1,5,5-tetramethyl-$-hexamethyleueaminodithiobiuret.

9 Ccbaltous chloride adduct of1,1,5,5-tetramethyl3-carbethoxyaminodithiobiuret.

10 Manganous chloride adduct ofl,l,5,5-tetramethyl-3-dinpropylaminodithiobiuret.

ll Ferric bromide adduct of1,l,5,5-tetraethyl-3-diethylamu1odithiobiuret.

12 Ferric chloride adduct of 1,l-dimethyl-3-dimethylanlino-5,5-di-n-propyl-dithiobiuret.

13 Ferric chloride adduct of l,l,5,5-tetramethyl-3-(N-methyldodecylamino)dithiobiuret.

14 Ferric chloride adduct of l,1-dimethyl-3-dimethylamino-5,5-di-n-hexyldithiobiuret.

15 Ferric chloride adduct of 1,l.-dimethyl-3-dimethylamino-5,5-pentamethylenedithiobiuret.

16 Ferric chloride adduct of l,1,5,5-tetrarnethyl-3-(N-methyl anilino)dithiobiuret.

17 Ferric chloride adduct of l,1,5-trimethyl-3-dimethylamino-E-n-dodecyldithiobiuret.

18 Ferric chloride adduct of 1,1-dimethyl-3-dirnethylamino-5,5-(3-oxotetramethylene) dithiobiuret.

19 Ferric chloride adduct of 1,1,6,5-di(3-oxotetramethylene)dimethylaminodithiobiuret.

20 Ferric chloride adduct of1,l-pentamethylene-3-dimcthylamino-5,5-(3-oxotetramethylene)dithiobiuret.

21 Ferric chloride adduct; of1,1,5,5-di(pentamethylene)-3-dimethylaminodithiobiuret.

22 Ferric chloride adduct of 1,1,fi-trimethyl-S-dimethyl-amino-S-phenyldithiobiuret.

23 Ferric chloride adduct of1-methyl-l-phenyl-3-dimethylamino-5-ethyl-5-cyclohcxyl-dithiobiuret.

24 Ferric chloride adduct of 1,1-dimethyl-3-dimethylamino-5ethyl-5-phenyl dithiobiuret.

25 Ferric chloride adduct of 1 l-dimethyl-B-dimethylemme-5-methyl-5-(4-chlorophenyl3dithiobiuret.

26 Ferric chloride adduct of 1,1-dimethyl-3-dimethylamino-5-methyl-S-(4-methylphenyl) dithiobiuret.

27 Ferric chloride adduct of 1,1-dimethyl-3-dimethyla.mino-5-methyl-5(4-methylthiophenyl) dithiobiuret.

28 Ferric chloride adduct of1,5-dimethyl-1,5-diphenyl-8-dimethylaminodithiobiuret.

29 Ferric chloride adduct of1,1,5-trimetl1yl-3-dimethylaminofi-benzyldithiobiuret.

30 Ferric chloride adduct of1,1,5-trimethyl-3-hexamethyleneamino-5-phenyldithiobiuret.

31 Ferric chloride adduct ofl,1,5-trimethyl-3-pentamethyleneamino-E-phenyldithiobiuret.

32 Ferric chloride adduct of 1,l,5,5-tetramethyl-BlN-methyl(6]chloropyridyl)aminoldithiobiuret.

33 Ferric chloride adduct of l,1-dimethyl-3-dimethylamino-5-n-propyl-fi-phenyldithiobiuret.

34 Ferric chloride adduct of 1,1-l(N-methyl)-3-aminotetra]glethylene]-3-dirnethylamino-5-rnetliyl-5-phenyldithiciure 35 Ferricchloride adduct of l,5-dirnethyl-1,5-diphcnyl-3-N- methylanilinodithiobiuret.

36 Ferric chloride adduct 01' l,l-dimethyl-3-dimethylamino5,5-di(cyanomethyl)dithiobiuret.

37 Ferric chloride adduet of 1,l-dimethyl-3-dimethylamino-5-phenyl-5-carboethoxymethylenedithioloiuret.

38 Ferric chloride adduct of 1,1-dimethyl-3-dimethylamino-5-methyl-fi-furiuryldithiobiuret.

39 Ferric chloride adduct of 1,1-dimethyl-3-dimethylamino-5-phenyl-fi-benzyldithiobiuret.

4O Ferric chloride adduct of 1,1,5-trimethyl-B-dimethylamino-5-(2-picolyl) dithiobiuret.

41 Ferric chloride adduct of1,1,5-trimethyl-3-dimethyl-aminofi-tetrahydrofurfuryldithiobiuret.

42 Ferric chloride adduct of 1,1-dirnethyl-3-dimethylamino-5-phenyl-fi-N-acetamidodithiobiurct.

The dithiobiurets which are the starting materials for forming the metalcomplexes of the subject invention are described in a copending case,Ser. No. 821,975 which was filed on May 5, 1969, now abandoned, in thename of James Zielinski and entitled Semicarbazide and BiuretDerivatives and Their Uses as Agricultural Pesticides and Animal HealthAgents.

The metal complexes can be prepared according to the following reaction:

wherein R -R MXn are defined as hereinabove. This reaction can becarried out under a temperature ranging from 10 C. to 250 C., preferably10 C. to 30 C. in

the presence of solvents such as acetone, dimethyl formamide,tetrahydrofuran, ethanol, methanol, propanol and water. Preferredsolvent is acetone. The mole ratio of the dithiobiuret to the halideranges from 1:3 to 3 :1 and preferably in the range of equal molarratios of 1:1. The reaction can be run under atmospheric pressure. Theconcentration of the reactants in the solvent is of no consequence.

The compounds may be applied to the plants in a number of ways any timethroughout the growing season depedning on the type of effect desired.When used the metal complexes of the dithiobiurets are preferablyformulated with a suitable inert carrier or diluent thereof.

The term carrier or diluent as used herein means a material, which canbe inorganic or organic and synthetic or of natural origin, with whichthe active metal complexes of the dithiobiurets are mixed or formulatedto facilitate its storage, transport, and handling and application ofthe plants or fungi to be treated. The carrier is preferablybiologically and chemically inert, and as used, can be a solid or fluid.When solid carriers are used, they are preferably particulate; however,other shapes and sizes of solid carrier can be employed as well. Suchpreferably solid carriers can be natural occurring minerals, althoughsubsequently subjected to grinding, sieving, purification, and/ or othertreatments, including for example, gypsum; tripolite diatomaceous earth;mineralsilicates such as mica, vermiculite, talc and pyrophyllite, claysof the montmorillonite, kaolinite, or attapulgite groups; calcium ormagnesium limes, or calciate and dolomite; etc. Carriers producedsynthetically, as for example, synthetic hydrated silica oxides andsynthetic calcium silicates can also be used, and many proprietaryproducts of this type are available commercially. The carrier can alsobe an elemental substance such as sulfur or carbon, preferably anactivated carbon.

Fluid carriers can be liquids, as for example, water, or an organicfluid, including a liquefied normally vaporous or gaseous material, or avaporous or gaseous material, and can be solvents or nonsolvents for theactive material. For example, the horticultural petroleum spray oilsboiling in the range of from about 275 F. to about 575 E, or boiling inthe range of about 575 F. to about 1,000 F. and having an unsulfonatableresidue of at least about and preferably of at least about 90%, ormixtures of these two types of oil, are particularly suitable liquidcarriers.

The carrier can be mixed or formulated with the active material duringits manufacture or at any stage subsequently. The carrier can be mixedor formulated with the active material in any proportion depending onthe nature of the carrier. One or more carriers, moreover, can be usedin combination.

The compositions of this invention can be concentrates, suitable forstorage or transport and containing, for example, from about 5 to about90% l y weight of the active dithiobiuret metal complexes, preferablyfrom about 20 to about wt. percent. These concentrates can be dilutedwith the same or different carrier to a concentration suitable forapplication. The compositions of this invention may also be dilutecompositions suitable for application. In general, concentrations ofabout 0.1 to about 10% by Weight, of active material based on the totalweight of the composition are satisfactory, although lower and higherconcentrations can be applied if necessary.

The compositions of this invention can also be formulated as dusts.These comprise an intimate admixture of the active dithiobiuret metalcomplex and a finely powdered solid carrier such as aforedescribed. Thepowdered carriers can be oil-treated to improve adhesion to the surfaceto which they are applied. These dusts can be concentrates, in whichcase a highly sorptive carrier is preferably used. These requiredilution with the same or a different finely powdered carrier, which canbe of lower isorptive capacity, to a concentration suitable forapplication.

The compositions of the invention can be formulated as wettable powderscomprising a major proportion of the dithiobiuret metal complex mixedwith a dispersing, i.e., defiocculating or suspending agent, and, ifdesired, a finely divided solid carrier and/or a wetting agent. Thedithiobiuret metal complex can be in particulate form or absorbed on thecarrier and preferably constttute at least about 10%, more preferably atleast about 25%, by weight of the composition. The concentration of thedispersing agent should in general be between about 0.5 and about byweight of the total composition, although larger or smaller amounts canbe used if desired.

The dispersing agent used in the composition of this invention can beany substance having definite dispersing, i.e., deflocculating orsuspending properties, as distinct from wetting properties, althoughthese substances can also possess wetting properties as well.

The dispersant or dispersing agent used can be protective colloids suchas gelatin, glue, casein, gums, or a synthetic polymeric material suchas polyvinyl alcohol and methyl cellulose. Preferably, however, thedispersants or dispersing agents used are sodium or calcium salts ofhigh molecular weight sulfonic acids, as for example, the sodium orcalcium salts of lignin sulfonic acids derived from sulfite cellulosewaste liquors. The calcium or sodium salts of condensed aryl sulfonicacid, for example, the products known as Tamol 731 are also suitable.

The wetting agents used can be nonionic type surfactants, as forexample, the condensation products of fatty acids containing at least12, preferably 16 to 20, carbon atoms in the molecule, or abietic acidor naphthenic acid obtained in the refining of petroleum lubricating oilfractions with alkylene oxides such as ethylene oxide or propyleneoxide, or with both ethylene oxide and propylene oxide, as for example,the condensation product of oleic acid and ethylene oxide containingabout 6 to 15 ethylene oxide units in the molecule. Other nonionicWetting agents like polyalkylene oxide polymers, commercially known asPluronics can be used. Partial esters of the above acids with polyhydricalcohols such as glycerol, polyglycerol, sorbitol, or mannitol can alsobe used.

Suitable anionic wetting agents include the alkali metal salts,preferably sodium salts, of sulfuric acid esters or sulfonic acidscontaining at least 10 carbon atoms in a molecule, for example, thesodium secondary alkyl sulfates, dialkyl sodium sulfosuccinate availableunder the registered trademark Teepol, sodium salts of sulfonated castoroil, sodium dodecyl benzene sulfonate.

The final wettable powder should preferably have an average particlesize of 5-10 'Where the toxicant itself is a liquid, these materials canbe sprayed on crops or fungi without further dilution.

Petroleum hydrocarbon fractions used as solvents should preferably havea flash point above 73 R, an example of this being a refined aromaticextract of kerosene. Auxiliary solvents such as alcohols, ketones, andpolyal kylene glycol ethers and esters can be used in conjunction withthese petroleum solvents.

The treatment rates range from .1 to 3 lbs/acre of the activeingredients with a preferred range of .1 to /3 1-bs./ acre. Thematerials are applied at optimum timing so as to have the desired effecton the particular crop. Therefore, applications may be made once or morethan once depending on plant species or varieties, cultural conditions,environmental conditions for the particular type of effect desired.

In addition to defining activity as growth regulants, the subject metalcomplexes also possess fungicidal activity. In order to demonstrate theeffectiveness of these compounds as growth regulants and as fungicides,the following examples are hereinafter presented.

6 EXAMPLE 1 In order to demonstrate the fungicidal activity of thesecompounds of the subject invention, aqueous solutions of the activecompounds were prepared by mixing the active ingredients with varyingamounts of acetone as an auxiliary solvent, adding thereto parts permillion by weight of a commercial wetting agent consisting of Triton X100 and diluting this premixture with Water to the desired concentrationindicated in the table hereinbelow. Triton X 100 is one of a line ofcommercial surfactants produced by Rohm and Haas Company and is a liquidalkyl aryl polyether alcohol that is an acid stable detergent and isnonionic in character as an emulsifier. It is prepared by reaction of analkylphenol with ethylene oxide.

The spray solution containing the active fungicide was applied as aprotectant spray to tomato plants. After the deposit had dried,Phytophthora Infestans spores were applied. Disease ratings were takenin 7-10 days. The results are shown in Table I.

TABLE I.FUNGICIDAL ACTIVITY [Late blight activity of metal complexes]Percent control ferric chloride adduct of 1,1,5,5-tetramethyl 3-dimethylaminodithiobiuret Percent control zinc chloride adduct of1,1,5,5-tetramethyl 3- dimethylaminodithiobiuret Rates, p.p.m.(acetone-water solution) EXAMPLE 2 I application of a 5 gram pressure tothe outer portion of the petiole. The treated plants exhibit acceleratedpetiole abscission as shown by the following data for each replica.

TABLE II Days to cotton petiole 7 day growth regulant s abscissioneffect on bean seedlin gs No efiect. 2 New growth abscissed.

Compound Treatment, lanolin only, control.. 6 Ferric chloride adduct of1,1,5,5-

tetrarnethyl 3-dimethylarninodithiobiuret.

In the stability test procedure the dithiobiuret ingredient is depositedon a piezoelectric quartz crystal which functions as a sensitivemicrobalance. When electrically excited, the high frequency vibrationsof the quartz plates are inversely proportional to the mass of thematerial present on the plate, whereby the change in frequency iscalibrated as a rate of loss in Weight due to decomposition of thedithiobiuret ingredient. Then change in weight is noted in grams perminute per cm. as a function of the exposure to an ultraviolet lightsource when compared with the visible light containing no ultravioletingredient. The results of the stability test are given in Example 3.

[Effect of metal complexing of dithiooiurets on maintaining theirstability against U.V. exposure] Volatility rate at 80 F.,gms./mir1./cm. 2

Visible U.V.

Sample light only exposure 1,%,5-tatramethyl-B-dimethylaminodithio- Nil7.6X10- lure Ferric chloride adduct of 1,1,5,5-tetramethyl-3- Nil Nil.

dimethylaminodithiobiuret. Zinc chloride adduct of1,1,5,5-tetramethyl-3- Nil Nil.

dimethylaminodithiobiuret.

This example definitely shows that metal complexing of the dithiobiuretsdoes provide the resulting complex with stability towards U.V.degradation to which the parent compound demonstrates instability.

In summary, the unique properties of these compounds are useful asabscission-control agents to adjust the rate and timing of abscission offlowers, fruits, (including citrus stone, pome fruits), nuts, berries,floral and vegetable crops; as mature crop harvest aids applied to laterstages of the maturing crop to control the rate of final development andmaturation of the crop and regulate the timed abscission of the maturefruit, vegetables, nuts or berries; as foliar maturation control agentsapplied to forage, turf, horticultural and ornamental plants or crops todelay the onset of normal maturation processes such as senescence ordefoliation thereby providing continued vegetative growth and/ or moreintensely colored foliage so as to provide higher yields of forage cropsand more desirable foliage on other plants and turfs; as crop-pruningagents applied to cucurbits and other vine crops and indeterminatevegetables several days or weeks prior to harvesting to stimulateabscission of young fruit and flowers, leaving only the earlier settingor maturing fruit for subsequent harvest during a concentrated timeperiod; as plant sex expression modifiers applied to cucurbits toincrease the ratio of female to male flowers thereby increasingsubsequent crop yields; as a preventative of sucker shoots from growingon tobacco plants thereby stepping up the prime leaf yield so as toreduce the growers costs; as a preventative of wrinkling and shrinkingor softening of fresh vegetables when stored or shipped; as apreventative of the sprouting of onions and potatoes when in storage.

The plant growth regulants mentioned hereinabove, although safe tohandle, and operative under very favorable conditions over a longerperiod of application time, nevertheless must be employed within arelatively narrow limit of concentration or else overthinning, epinasty,and other serious damage to foliage and shoots will occur.

What is claimed is:

1. A compound of the formula wherein each of R R R R R and R is C -Calkyl; M is a metal selected from the group consisting of iron, cobaltand nickel; and X is an anion selected from the group consisting ofchloride, bromide, iodide, sulfate, nitrate, phosphate and acetate; andn is an integer determined by the valence of the metal atom.

2. A compound according to claim 1 which is the ferric chloride adductof 1,1,5,5-tetramethy1-3-dimethylaminodithiobiuret.

3. A compound according to claim 1 which is the ferric iodide adduct of1,1,5,5-tetraethyl-3-diethylaminodithiobiuret.

4. A compound according to claim 1 which is ferric chloride adduct of1,1-dimethyl-3-dimethylamino-5,5-di-npropyl dithiobiuret.

5. A compound according to claim 1 which is ferric chloride adduct of1,l-dimethyl-E-dimethylarnino-5,5-din-hexyldithiobiuret.

References Cited FOREIGN PATENTS 1,015,136 7/1952 France.

OTHER REFERENCES Usatenko et a1. Chem. Abst. 1964, columns 12641-2.

TOBIAS E. LEVOW, Primary Examiner A. P. DEMERS, Assistant Examiner US.Cl. X.R.

7l94, 95, 97; 260242, 270 R, 326.82 R, 429 R, 429.9, 438.1, 552 R, 553B, 554; 424-267, 274, 287, 289, 294,

